topic Re: Formula-driven Family Type parameter. in Revit Architecture Forum

Formula-driven Family Type parameter.

Anonymous — Mon, 09 Oct 2017 10:50:22 GMT

In my Family I have a parameter of type <Family Type>. I want it to be controlled by a formula. I have problems with defining this formula. For the simplest example i just copy the whole name of family and the type and paste to the formula field. I receive an error (see picture below). What is the correct way of typing type names into the formula field?

Re: Formula-driven Family Type parameter.

Sahay_R — Mon, 09 Oct 2017 12:50:12 GMT

The highlighted item in the screenshot is what really needs to be in the formula. Watch out for cases and typos!

Re: Formula-driven Family Type parameter.

Anonymous — Mon, 09 Oct 2017 14:34:50 GMT

Thank you for your reply, but could you please be more specific about the syntax? I was trying different Options (for example Abtropfbrett Typ<IPN_Abtropfbrett : 300 mm> but nothing works.

Re: Formula-driven Family Type parameter.

Sahay_R — Mon, 09 Oct 2017 14:35:55 GMT

Parameters are all in the extreme left column. From your screenshot, it appears that the formula includes information from the middle column. If I am incorrect, then a clearer screenshot with the error message moved away from the dialog box would be appreciated.

Here's how parameters are organized in the dialog box-

1) Left column = Parameter

2) Middle column = Parameter Value

3) Right column = formula, if any

The Formula is made out of Parameters, which will come from the left column.

Re: Formula-driven Family Type parameter.

Anonymous — Mon, 09 Oct 2017 14:42:54 GMT

You're right. In the formula field I tried the simplest possible way of assigning Parameter value using a formula. If the Parameter type would be let's say Integer, then if in formula field I would type "500", the Parameter Value would be set to 500. Apparently Family Type Parameters require different Syntax of formulas which is unknown to me.

Re: Formula-driven Family Type parameter.

Sahay_R — Mon, 09 Oct 2017 14:51:35 GMT

What exactly is it that you want your formula to do?

Re: Formula-driven Family Type parameter.

Anonymous — Mon, 09 Oct 2017 15:48:34 GMT

I want the parameter value equal IPN_Abtropfbrett : 300 mm if the value of Lenght is over 300 and IPN_Abtropfbrett : 600 mm otherwise.

Normally it would be something like if(Lenght>300,"IPN_Abtropfbrett : 300 mm","IPN_Abtropfbrett : 600 mm")

Re: Formula-driven Family Type parameter.

Alfredo_Medina — Mon, 09 Oct 2017 16:05:42 GMT

Family Type parameters cannot be set to a formula in a simple way. You need more parameters, one Family Type parameter for each variation, and one integer parameter to define which variation.

There is an example of this technique in "Exercise # 6" of this article that I posted in Linkedin:

https://www.linkedin.com/pulse/repetitions-randomness-revit-part-2-alfredo-medina/

Re: Formula-driven Family Type parameter.

Alfredo_Medina — Wed, 25 Oct 2017 10:38:23 GMT

Hello, @Anonymous

Just curious, what was the end of this case?

Re: Formula-driven Family Type parameter.

Grigor_Panosyan — Thu, 24 Oct 2019 14:38:07 GMT

The way you suggested in exercise 6 doesn't seem to work, I have tried to recreate the Hexagon family exactly as it is displayed in the Type Properties, but all I get is "The following parameter is not valid" after inserting the formula. I want to find out the right way of connecting Integer and Family Type parameters via a formula, but, unfortunately, I have no luck doing it.

Re: Formula-driven Family Type parameter.

Peter.Banski — Thu, 06 Aug 2020 13:19:45 GMT

Thank You Alfredo,

Your Link is the one and only solution in the whole WWW that I found, how to steer "Family Type Parameter" with a Formula.

And it works very well!

Peter

Re: Formula-driven Family Type parameter.

Alfredo_Medina — Mon, 14 Sep 2020 12:59:37 GMT

@Grigor_Panosyan wrote:

"The way you suggested in exercise 6 doesn't seem to work, ..."

_________________________________________________

Please try again. It does work.

Re: Formula-driven Family Type parameter.

Grigor_Panosyan — Thu, 05 Nov 2020 11:59:33 GMT

Dear @Alfredo_Medina, it does work like a charm, indeed I was doing something wrong back when I posted my reply.

Integer x Double Family Type x "if" statement became one of my favorite technics

Re: Formula-driven Family Type parameter.

Roberto.CabanasEPSPH — Thu, 31 Mar 2022 10:45:01 GMT

Great!!! Brilliant explanation and technique.

Re: Formula-driven Family Type parameter.

jquarry — Mon, 07 Nov 2022 14:05:26 GMT

Is this still the best (and only) way to drive Family Type Parameters in formulas?

Now that it is 2022 I figured I might save someone some time doing any additional searching...

Re: Formula-driven Family Type parameter.

Alfredo_Medina — Wed, 04 Oct 2023 21:42:48 GMT

Hello, @Peter.Banski and all of you participating in this thread. I want to add that I have made a video about this topic, how to control family types by formula, plus another topic, how to apply random values to those family types. If you're interested, please follow this link:

https://www.youtube.com/watch?v=_8Md-Vrw8PU

Re: Formula-driven Family Type parameter.

adriansin_randalllamb — Wed, 04 Oct 2023 19:23:36 GMT

Adding to @Alfredo_Medina 's solution. The formulas also work with Yes/No checkboxes. Yes/No checkboxes can be more intuitive for users. Thank you so much for the solution.

Re: Formula-driven Family Type parameter.

Rafael_Lucki1 — Wed, 08 May 2024 11:39:45 GMT

don't use this type family parameter, use visibility parameter to turn of other familys nested on you main because it does work better to write formulas

Re: Formula-driven Family Type parameter.

naylin.oo — Mon, 29 Sep 2025 08:09:32 GMT

Thanks a lot, it very helpful for me.